As shown in FIG. 1, a conventional electric nail gun 1 disclosed in Taiwanese Patent No. 1422470 includes a supporting frame 10, a nail passage 11 formed at a front end portion of the supporting frame 10 and for receiving a nail 21, a trigger unit 12 pivotally mounted to the supporting frame 10 and controllable by a control circuit to trigger a nail striking operation, a transmission unit 13, an impact unit 14 and a driving unit 15. The transmission unit 13 includes a flywheel 131 pivotally mounted to the supporting frame 10, and a motor 132 mounted to the supporting frame 10 and driving a high speed rotation of the flywheel 131. The impact unit 14 includes a swing arm 141 pivotally mounted to the supporting frame 10 and rotatable relative to the flywheel 131, and an impact member 142 slidable relative to the swing arm 141. The driving unit 15 includes a solenoid valve 151 mounted to the supporting frame 10, a slant push block 152 abutting against one end of the swing arm 141, and a connecting rod 153 pivotally mounted to the supporting frame 10.
Normally, the impact member 142 is spaced apart from the flywheel 131 at a distance that is 0.5 millimeters. During operation, when the trigger unit 12 is triggered, the solenoid valve 151 drives the connecting rod 153 to push the slant push block 152 to thereby move the slant push block 152 the swing arm 141 toward the flywheel 131 so that, the impact member 142 comes into contact with the flywheel 131 and then is thrown to strike the nail 21 to complete the nail striking operation.
However, since the slant push block 152 is biased to press against an upper end of the connecting rod 153, a resistance is created to impede activation of the solenoid valve 153, thereby adversely affecting smooth nail striking operation.